title: Repulsive interaction can be a key design element of molecular rotary motors.
abstract: Low-barrier molecular rotary motors having rotaxane architecture can be constructed using a cucurbituril host and a polyyne guest serving as stator and rotator, respectively. The repulsive interaction between these components is supported by molecular mechanics calculations with model systems and experimentally verified by X-ray crystallography with several synthetic host-guest complexes, all suggesting that the diyne rod floats at the center of the macrocyclic host with no apparent van der Waals contacts between them. Further support for these interactions is suggested by microcalorimetry measurements.
authors.affiliation: Schulich Faculty of Chemistry, Technion-Israel Institute of Technology, Technion City, Haifa 32000, Israel.
authors.forename: Irina
authors.initials: I
authors.lastname: Ben Shir
authors.forename: Sanjita
authors.initials: S
authors.lastname: Sasmal
authors.forename: Tom
authors.initials: T
authors.lastname: Mejuch
authors.forename: Mantosh K
authors.initials: MK
authors.lastname: Sinha
authors.forename: Moshe
authors.initials: M
authors.lastname: Kapon
authors.forename: Ehud
authors.initials: E
authors.lastname: Keinan
mesh_terms: D001952:Bridged-Ring Compounds / Q000737:chemistry; D002151:Calorimetry; D018360:Crystallography, X-Ray; D007093:Imidazoles / Q000737:chemistry; D053279:Polyynes / Q000737:chemistry; D043862:Rotaxanes / Q000138:chemical synthesis* / Q000737:chemistry; D013816:Thermodynamics; D017186:Titrimetry; D047028:Macrocyclic Compounds; D000099246:Cucurbit(n)urils
chemical_list: D001952:Bridged-Ring Compounds; D007093:Imidazoles; D053279:Polyynes; D043862:Rotaxanes; C454805:cucurbit(6)uril; D047028:Macrocyclic Compounds; D000099246:Cucurbit(n)urils